The present invention relates generally to electrical connectors and is more particularly concerned with a novel printed circuit board connector which retains the simplicity inherent in conventional printed circuit board connectors and yet provides protection for both the printed circuit board and the electrical contacts within the connector upon repeated insertions and withdrawals of the printed circuit board.
Conventional printed circuit board connectors generally include a plurality of separate electrical contacts which are spring biased metallic members. These members usually act against the printed circuit board during the insertion of the board into the connector. These contact members maintain a generally constant pressure against the surface of the printed circuit board until that board has been withdrawn from the connector. This continuous pressure is intended to insure adequate electrical contact with a conductor on the surface of the printed circuit throughout the useful life of board and connector board.
Two principal disadvantages are encountered with respect to such a connector during extended usage. Firstly, to insure adequate electrical contact between contact members and the printed circuit board, significant spring biasing forces are required to be associated with the contact members. When the printed circuit board is inserted into the connector body, the board and contact member each encounter these forces at the edge where, as a result of the force concentration at the edge, the edge is susceptible to damage after a number of insertions. As a result, wear or damage to the contact member increases significantly through contact with the damaged edge of the board. Secondly, the electrical contact on the member is generally made to a conductive strip on the printed circuit board through the use of a precious metal (often gold) at the point of contact. The extensive rubbing of the member at the point of contact at the edge of the board along the board material and along the conductive members during the insertion of the board into the connector causes excessive wearing of the precious metal as it is in constant contact with the board during insertion.
Numerous attempts have been made to alleviate either or both of the foregoing problems. These potential solutions include increasing the amount of precious metal utilized in the contact, which necessarily involves a significant increase in the cost of production of such connectors. Other connectors have utilized complex mechanical arrangements to alleviate mechanical contact between the printed circuit board and the connector members during the insertion of the printed circuit board into the connector. Most such arrangements result in connectors in which the number of components and their mechanical interrelationships are increased greatly, thereby further augmenting the cost of such connectors.